Sensor device and antenna, and systems and methods for obtaining and transmitting measurements of selected characteristics of a concrete mixture

ABSTRACT

A system includes a sensor device having a sensor adapted to generate measurement data relating to a characteristic of a concrete mixture, a transmitter adapted to transmit a first signal based on the measurement data, and a conductive wire forming a coil having a plurality of loops around the sensor device and a wire antenna. The coil is adapted to generate an electric current in response to the first signal. The antenna is adapted to transmit a second signal based on the electric current. The system is embedded in a concrete mixture and a portion of the antenna is exposed above the surface of the concrete mixture. A current is induced in the coil due to electromagnetic induction. A second signal is transmitted via the wire antenna. The second signal is received and transmitted to a processor. The processor may analyze and/or store the signal.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. Provisional Application No.62/565,318 filed Sep. 29, 2017 and from U.S. Provisional Application No.62/687,276 filed Jun. 20, 2018, the contents of which are incorporatedherein by reference.

TECHNICAL FIELD

This specification relates generally to the construction field, and moreparticularly to a sensor device and antenna, and systems and methods forobtaining and transmitting measurements of selected characteristics of aconcrete mixture.

BACKGROUND

Concrete is generally used within the industry to refer to a mixture ofcement, sand, stone, and water which upon aging turns into a hardenedmass. The term concrete, as used in the specification and claims herein,means not only concrete as it is generally defined in the industry(cement, sand and stone), but it also means mortar (cement, sand andwater) and cement (cement and water which hardens into a solid mass uponaging).

In the construction field, after a batch of concrete has been producedfor use at a particular site, it is useful to be able to obtain dataconcerning certain performance characteristics such as the in-placestrength of the batch, maturity, and other characteristics. Accurateprediction of concrete performance can increase the quality of the endproduct, and can provide other benefits such as allowing the use ofaccelerated construction schedules.

Several methods for testing and monitoring in-place strength of aconcrete mass have been incorporated into the American Standard TestingMethods, including ASTM C805 (The Rebound Number Method—the so-calledSwiss Hammer Method), ASTM C597 (The Pulse Velocity (Sonic) Method), andASTM C900 (The Pullout Strength Method).

In accordance with standards set forth in ASTM C31 (Standard Practicefor Making and Curing Concrete Test Specimens in the Field), thecompressive strength of concrete is measured to ensure that concretedelivered to a project meets the requirements of the job specificationand for quality control. In order to test the compressive strength ofconcrete, cylindrical test specimens are cast in test cylinders andstored in the field until the concrete hardens.

In accordance with the standards, typically 4×8-inch or 6×12-inch testcylinders are used, and the concrete specimens are stored in a carefullyselected location for a predetermined period of time. When makingcylinders for acceptance of concrete, the field technician must testproperties of the fresh concrete including temperature, slump, density(unit weight) and air content.

SUMMARY

In accordance with an embodiment, a sensor device includes a housing,the housing having an opening allowing substances to pass from anexterior of the housing to an interior of the housing, a printed circuitboard disposed in the housing, the printed circuit board including ahumidity sensor and at least one electronic component, a tube having afirst end and a second end, the tube comprising a waterproof material,wherein the first end of the tube surrounds the humidity sensor, whereina first seal is formed by between the first end of the tube and theprinted circuit board, wherein the second end of the tube is locatedproximate the hole, and a material layer disposed between the second endof the tube and the hole, wherein the material layer comprises awaterproof and breathable material, wherein a second seal is formedbetween the material layer and the housing, wherein a third seal isformed between the material layer and the second end of the tube. Thehole and the material layer allow water vapor to pass from the exteriorto the humidity sensor. The first seal, the second seal, and the thirdseal prevent the water vapor from reaching the at least one electroniccomponent.

In one embodiment, the printed circuit board further comprises one of atemperature sensor, an accelerometer, a pH sensor, an inductance sensor,an impedance or resistivity sensor, a sonic sensor, a pressure sensor, aconductivity sensor, a salinity sensor, a humidity sensor, and anelevation sensor.

In another embodiment, the printed circuit board further includes atransmitter.

In another embodiment, the tube comprises one of plastic and rubber.

In another embodiment, the tube has a diameter of between 0.25 cm and1.0 cm.

In accordance with another embodiment, a sensor device includes ahousing, the housing having an opening that allows water vapor to passbetween an exterior of the housing and an interior of the housing butprevents liquid from passing between the exterior and the interior. Thesensor device also includes a printed circuit board disposed in thehousing, the printed circuit board including a humidity sensor adaptedto obtain humidity measurements, one or more second sensors adapted toobtain measurement data, and a processor adapted to: detect a change inthe humidity measurements from a first level to a second level, activatethe one or more second sensors in response to the change in the humiditymeasurements, and a transmitter adapted to transmit the humiditymeasurements and the measurement data.

In one embodiment, the opening comprises a hole in the housing, the holehaving a diameter between 0.5 millimeters and 1.0 millimeter.

In another embodiment, the housing comprises a first portion and asecond portion, the first and second portions being engaged, and theopening is disposed between the first and second portions.

In another embodiment, the printed circuit board further comprises oneof a temperature sensor, an accelerometer, a pH sensor, an inductancesensor, an impedance or resistivity sensor, a sonic sensor, a pressuresensor, a conductivity sensor, a salinity sensor, a humidity sensor, andan elevation sensor.

In accordance with another embodiment, a method is described. The methodincludes detecting, by a sensing device, a first humidity levelrepresenting a humidity of a first environment, embedding the sensingdevice within a concrete mixture, detecting, by the sensing device, asecond humidity level associated with the concrete mixture, determininga change in humidity between the first humidity level and the secondhumidity level, and activating a selected component of the sensingdevice in response to detection of the change in humidity.

In one embodiment, the selected component comprises one of a temperaturesensor, an accelerometer, a pH sensor, an inductance sensor, animpedance or resistivity sensor, a sonic sensor, a pressure sensor, aconductivity sensor, a salinity sensor, a humidity sensor, and anelevation sensor.

In accordance with another embodiment, a sensor device is provided. Thesensor device includes a housing, the housing having a hole allowingsubstances to pass from an exterior of the housing to an interior of thehousing, a printed circuit board disposed in the housing, the printedcircuit board including one of a temperature sensor and a humiditysensor, a material layer disposed between the hole and the printedcircuit board, wherein the material layer comprises a waterproof andbreathable material, and a support element disposed between the printedcircuit board and the material layer, the support element adapted toseparate the printed circuit board and the material layer. The hole andthe material layer allow water vapor to pass from the exterior to theinterior of the housing.

In accordance with another embodiment, a sensor device includes ahumidity sensor. Before being placed into a concrete mixture, selectedcomponents of the sensor device (such as a temperature sensor, a pHsensor, a motion sensor, an accelerometer, etc.) are deactivated. Thehumidity sensor obtains humidity measurements, and the humiditymeasurement data is monitored by a processor. At the time when thesensor is inserted into a concrete mixture, the processor detects achange in the humidity measurements. For example, a spike in humiditymay be detected. In response to the change in humidity, one or morecomponents of the sensor device are activated. For example, othersensors may be activated in order to obtain measurements of temperatureand other characteristics of the concrete mixture.

In accordance with another embodiment, a sensor device includes a sonicsensor adapted to measure sonic signals (sound waves). Before beingplaced into a concrete mixture, selected components of the sensor device(such as a temperature sensor, a pH sensor, a motion sensor, anaccelerometer, etc.) are deactivated. The sonic sensor obtainsmeasurements of sonic signals around the sensor device, and the sonicsignal measurement data is monitored by a processor. At the time whenthe sensor is inserted into a concrete mixture, the processor detects achange in the strength of the sonic signal. For example, after thesensor is inserted into the concrete mixture, a signal loss may bedetected as sonic signals (sound waves) are blocked by the concretemixture. In response to the change in the strength of the sonic signal,one or more components of the sensor device are activated.

In one embodiment, components of a sensor device, such as the housingand other parts, may be formed of a thermosetting resin or athermoplastic.

In one embodiment, a sensor device (such as any of those describedherein) may have a housing with a square or rectangular shape, with afirst side having a length between about 1.5 inch and about 2.0 inches,a second side having a length between about 1.5 inch and about 2.0inches, and a thickness between about one-eight inch and one-half inch.In a preferred embodiment, a sensor device has a housing with a squareshape with sides having a length of about one and three-fourths (1.75)inches, and a thickness of about three-sixteenth ( 3/16) inches.

In accordance with another embodiment, a system includes a sensor devicehaving a sensor adapted to generate measurement data relating to acharacteristic of a concrete mixture, and a transmitter adapted totransmit a first signal based on the measurement data. The system alsoincludes a conductive wire forming a coil having a plurality of loopsaround the sensor device and a wire antenna. The coil is adapted togenerate an electric current in response to the first signal. Theantenna is adapted to transmit a second signal based on the electriccurrent. The system is embedded in a concrete mixture and a portion ofthe antenna is exposed above the surface of the concrete mixture. Thesensor device obtains measurement data and transmits a signal related tothe measurement data. A current is induced in the coil due toelectromagnetic induction. A second signal is transmitted via the wireantenna. The second signal is received and transmitted to a processor.The processor may analyze and/or store the signal.

In one embodiment, the coil includes at least five loops.

In another embodiment, the conductive wire comprises a metal. Theconductive wire may be an insulated metal wire.

In another embodiment, the sensor device comprises a printed circuitboard having a plurality of sensors. The plurality of sensors mayinclude one of: a temperature sensor, an acceleration sensor, a motionsensor, a pH sensor, an inductance sensor, an impedance sensor, aresistivity sensor, a pressure sensor, a conductivity sensor, a salinitysensor, a humidity sensor, and an elevation sensor.

In another embodiment, the printed circuit board is disposed in a case.

In another embodiment, the sensor device is covered by a layer of aprotective material. The protective material may be rubber or plastic,or a different material.

In accordance with another embodiment, a sensor device includes ahousing, a sensor adapted to obtain a measurement, a wire extending fromthe housing, the wire having a length, the wire adapted to function asan antenna, and a transmitter adapted to transmit a signal via the wire,the signal having a wavelength related to the length of the wire. Insome embodiments, the sensor device may include more than one wireextending from the housing.

In one embodiment, the signal includes information relating to themeasurement.

In another embodiment, the wavelength of the signal is one of: twice thelength of the wire, the length of the wire, one-half the length of thewire, and one-fourth the length of the wire.

In another embodiment, a communication system includes a concretemixture, a sensor device embedded in the concrete mixture, and awireless router adapted to receive signals from the sensor device. Thewire(s) may be embedded entirely in the concrete mixture, or may extendabove the surface of the concrete mixture.

In one embodiment, the sensor includes one of a temperature sensor, anaccelerometer, a pH sensor, an inductance sensor, an impedance orresistivity sensor, a sonic sensor, a pressure sensor, a conductivitysensor, a salinity sensor, a humidity sensor, and an elevation sensor.

In accordance with another embodiment, a device includes a printedcircuit board comprising one or more sensors adapted to obtainmeasurement data and a first antenna adapted to transmit a first signalbased on the measurement data, a layer of a waterproof protectivematerial covering at least a portion of the printed circuit board, and aconductive wire having a first portion that is wound around the printedcircuit board to form a plurality of coils and a second portion thatfunctions as a second antenna. The plurality of coils of the conductivewire responds to the first signal due to inductive coupling, therebygenerating a second signal. The second antenna transmits the secondsignal. The protective material may be rubber or plastic, for example.

In one embodiment, the device is embedded in a concrete mixture.

These and other advantages of the present disclosure will be apparent tothose of ordinary skill in the art by reference to the followingDetailed Description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a sensor in accordance with an embodiment;

FIG. 2 shows components of the sensor of FIG. 1;

FIG. 3 shows a protective tube in accordance with an embodiment;

FIG. 4 shows a printed circuit board in accordance with an embodiment;

FIG. 5 shows a top view of an upper portion of a sensor in accordancewith an embodiment;

FIGS. 6-7 show cross-sectional views of components of a sensor inaccordance with an embodiment;

FIG. 8 shows a sensor disposed on a surface of a concrete mixture inaccordance with an embodiment;

FIG. 9 shows a sensor embedded beneath the surface of a concrete mixturein accordance with an embodiment;

FIG. 10 shows a concrete mixture in a form in accordance with anembodiment;

FIG. 11 shows a concrete mixture in a form in accordance with anotherembodiment;

FIG. 12 shows a test cylinder and a cap in accordance with anembodiment;

FIG. 13 shows a test cylinder and a cap placed on the test cylinder inaccordance with an embodiment;

FIG. 14 shows a cross-sectional view of components of a sensing devicein accordance with an embodiment;

FIG. 15 shows a view of a flat side of a portion of the sensing deviceof the embodiment of FIG. 14;

FIG. 16 shows a cross-sectional view of a sensing device in accordancewith an embodiment;

FIG. 17 shows a sensing device embedded in a concrete mixture inaccordance with an embodiment;

FIG. 18 shows a sensing device in accordance with another embodiment;

FIG. 19 shows a communication system in accordance with an embodiment;

FIG. 20 is a flowchart of a method in accordance with an embodiment;

FIG. 21A shows a sensor disposed on the surface of soil in accordancewith an embodiment;

FIG. 21B shows a sensor embedded under the surface of soil in accordancewith an embodiment;

FIG. 22 shows a high-level block diagram of an exemplary computer thatmay be used to implement certain embodiments;

FIG. 23A is a flowchart of a method of obtaining data relating tocharacteristics of a concrete mixture in accordance with an embodiment;

FIG. 23B shows a concrete structure in accordance with an embodiment;

FIG. 24A shows a sensor device in accordance with an embodiment;

FIG. 24B shows components of a sensor device in accordance with anembodiment;

FIG. 25 is a flowchart of a method of detecting humidity in a concretemixture in accordance with an embodiment;

FIG. 26A shows a construction site in accordance with an embodiment;

FIG. 26B is a graph showing humidity measurements versus time inaccordance with an embodiment;

FIG. 26C is a flowchart of a method in accordance with an embodiment;

FIG. 26D is a graph showing measurements of a sonic signal versus timein accordance with an embodiment;

FIGS. 27A-27C show components of a sensor device in accordance withanother embodiment;

FIG. 28 shows a sensor device and a cap adapted to be placed onto astandard concrete test cylinder in accordance with an embodiment;

FIGS. 29A-29D show a sensor device in accordance with anotherembodiment;

FIGS. 30A-30C show components of a sensor device in accordance withanother embodiment;

FIGS. 31A-31D show components of a sensor device in accordance withanother embodiment;

FIG. 32A shows a cap adapted to fit on a standard concrete test cylinderand a sensor device in accordance with an embodiment;

FIG. 32B shows a cap with a sensor device on a standard concrete testcylinder in accordance with an embodiment;

FIG. 33A shows a form containing a concrete mixture and a sensor devicein accordance with an embodiment;

FIG. 33B shows the sensor of FIG. 33A embedded in the concrete mixturewithin the form of FIG. 33A;

FIG. 34A shows components of a sensor device in accordance with anotherembodiment;

FIG. 34B shows a sensor device and a wire wound around the device,forming a plurality of loops, in accordance with an embodiment;

FIG. 34C shows sensor device and a coil having plurality of loops inaccordance with an embodiment;

FIG. 35 shows a form containing a concrete mixture in accordance with anembodiment;

FIG. 36 shows a container of water holding a body of water in accordancewith an embodiment;

FIG. 37 shows a sensor device in accordance with an embodiment;

FIG. 38 shows a communication system in accordance with an embodiment;

FIG. 39 shows a communication system in accordance with an embodiment;

FIG. 40 shows a sensor device in accordance with another embodiment;

FIG. 41 shows a concrete mixture containing several sensor devices inaccordance with an embodiment;

FIG. 42 shows a cross-section of a sensor device in accordance with anembodiment;

FIG. 43 shows a sensor device in accordance with another embodiment; and

FIG. 44 shows a sensor device in accordance with another embodiment.

DETAILED DESCRIPTION

It has been observed that embedding sensors into a concrete mixture canbe a useful method for obtaining certain measurements relating to theconcrete mixture. For example, embedding a temperature sensor in aconcrete mixture can facilitate the gathering of temperature data, whichcan be useful in predicting the strength or maturity of the concretemixture. Similarly, embedding a humidity sensor in a concrete mixturecan facilitate the gathering of humidity data, which can also be usefulin predicting the strength or maturity of the concrete mixture. Whenembedded in a concrete mixture, it is preferable that a humidity sensorbe directly exposed to the water vapor within the concrete in order todirectly measure the humidity of the concrete.

However, it has been observed that many types of sensors, such astemperature sensors, motion sensors, etc., are susceptible to damagewhen exposed to humidity. In addition, any electronics in a sensor mayalso be damaged by humidity. Therefore, it is often preferable toprovide a protective seal for certain sensors (e.g., temperaturesensors, motion sensors, etc.) and for any electronics on a sensorbefore embedding such sensors into a concrete mixture.

Accordingly, there is a need for improved systems, apparatus, andmethods for embedding a humidity sensor into a concrete mixture in amanner that exposes the humidity sensor to the humidity of the concretemixture, while protecting any electronic circuitry on the sensor, andany other attached sensors from exposure to the humidity of theconcrete.

FIG. 1 shows a sensor 100 in accordance with an embodiment. Sensor 100includes a housing 110. Housing 110 includes a hole 120.

FIG. 2 shows components of the sensor of FIG. 1. Sensor 100 includesupper portion 206 and lower portion 208 of housing 110. Housing 110 maycomprise plastic, metal, or other suitable material. Sensor may have awidth between 0.5 inch and 3 inches, for example. Other dimensions maybe used.

Sensor 100 also includes a layer 220 of waterproof material, aprotective tube 230, and a printed circuit board (PCB) 240. PCB 240includes a plurality of elements 248, which may include circuitcomponents such as resistors, capacitors, amplifiers, etc., and/or oneor more sensors adapted to obtain measurements relating to one or morecharacteristics such as temperature, motion, etc. For example, PCB 240may include one or more of the following: a temperature sensor, asalinity sensor, a conductivity sensor, a motion sensor, a pH sensor, anacceleration sensor, a sonic sensor, etc. PCB 240 also includes atransceiver 249, which may include an antenna capable of sending andreceiving data via wireless communication, for example. PCB 240 alsoincludes a humidity sensor 255. PCB 240 may also include a battery orother power source.

PCB 240 fits into bottom portion 208. Tube 230 fits onto and overhumidity sensor 255. A first end of tube that contacts PCB 240 surroundshumidity sensor 255. PCB 240 and tube 230 are constructed in such amanner that a seal is formed between tube 230 and PCB 240 when tube 230is fitted onto and over humidity sensor 255. A second end of tube has adiameter that is larger than hole 120; therefore the second end surroundhole 120.

Waterproof layer 220 fits above tube 230 between the second end of tube230 and hole 120. Waterproof layer 220 includes a waterproof, breathablematerial. Therefore, waterproof layer 220 allows water vapor that entershole 120 to pass through waterproof layer 220, but prevents water (or aconcrete mixture) from passing through. Waterproof layer 220 may beformed from a waterproof, breathable fabric membrane such as Gore-Tex orother similar material. Upper portion 206 fits onto lower portion 208,creating a protective seal.

FIG. 3 shows protective tube 230 in accordance with an embodiment. Tube230 may be formed of a waterproof material such as a plastic, rubber, orother material. Tube 230 has a diameter d1 that is determined by thesize of humidity sensor 255. Tube 230 surrounds humidity sensor 255;therefore the diameter d1 of tube 230 is greater than the greatestdimension of humidity sensor 255. In one embodiment, diameter d1 of tube230 is between 0.25 cm and 1.0 cm. Other diameters may be used.

FIG. 4 shows PCB 240 in accordance with an embodiment. PCB 240 includesa groove 475 surrounding humidity sensor 255. Groove 475 is adapted toreceive and support and end of tube 230.

FIG. 5 shows a top view of upper portion 206 in accordance with anembodiment. Hole 120 has a diameter d2. Diameter d2 is preferably equalto or smaller than diameter d1 of tube 230. However, any diameter may beused.

FIGS. 6 and 7 show cross-sectional views of components of sensor 100 inaccordance with an embodiment. PCB 240 fits into bottom portion 208.Tube 230 fits onto and over humidity sensor 255. PCB 240 and tube 230are constructed in such a manner that a first seal is formed betweentube 230 and PCB 240 when tube 230 is fitted onto and over humiditysensor 255. Waterproof layer 220 fits above tube 230. Upper portion 206fits onto lower portion 208, creating a protective seal between upperportion 206 and lower portion 208. As upper portion 206 is closed, aseal also forms between tube 230 and waterproof layer 220. FIG. 7 showsa cross sectional view of components of sensor 100 after upper portion206 has been fitted onto lower portion 208.

Advantageously, as upper portion 206 is closed over lower portion 208, afirst seal is formed between tube 230 and PCB 240, a second seal isformed between tube 230 and waterproof layer 220, and a third seal isformed between waterproof layer 220 and upper portion 206. After theseseals are formed, tube 230 defines a volume between hole 120 andhumidity sensor 255 that is partially exposed to the surroundingenvironment. Hole 120 allows water vapor to enter the interior of sensor100 and reach humidity sensor 255, enabling humidity sensor 255 tomeasure the humidity of the surrounding environment. Waterproof layer220 is breathable and allows water vapor to pass through to humiditysensor 255; however, waterproof layer 220 prevents any water (orconcrete mixture) from passing through to the interior of sensor 100. Inaddition, tube 230 advantageously prevents any water vapor that entersthrough hole 120 from reaching other components of sensor 100. Forexample, tube 230 protects components 248 (and transceiver 249) from thehumidity of the surrounding environment.

In accordance with an embodiment, sensor 100 may be used to obtainmeasurements of humidity of a concrete mixture. In one embodiment,sensor 100 may be placed on top of the surface of a concrete mixture,with hole 120 facing down (into the concrete mixture). In anotherembodiment, sensor 100 may be embedded within a concrete mixture. Forexample, sensor 100 may be embedded several inches or several feetbeneath the surface of a concrete mixture.

FIG. 8 shows sensor 100 disposed on a surface of a concrete mixture 825in accordance with an embodiment. Hole 120 faces downward, proximate thesurface of concrete 825. Because hole 120 faces downward, water vaporfrom concrete mixture 825 readily passes through hole 120, and throughlayer 220, and reaches humidity sensor 255. Humidity sensor 255 mayobtain humidity measurements of the humidity of concrete mixture 825.Sensor 100 may transmit the humidity measurements to a second device viawireless transmission, for example.

FIG. 9 shows sensor 100 embedded beneath the surface of a concretemixture 925 in accordance with an embodiment. Hole 120 faces downward.Water vapor from concrete mixture 925 readily passes through hole 120,and through layer 220, and reaches humidity sensor 255. Humidity sensor255 may obtain humidity measurements of the humidity of concrete mixture925. Sensor 100 may transmit the humidity measurements to a seconddevice via wireless transmission, for example. In the illustrativeembodiment, sensor 100 may transmit data wirelessly through a layer ofconcrete.

Sensor 100 may be used in this manner at a construction site, forexample. FIG. 10 shows a concrete mixture 1020 in a form 1010 inaccordance with an embodiment. Sensor 100 is disposed on the surface ofthe concrete. Sensor 100 may obtain measurements of the humidity ofconcrete mixture 1020. Sensor 100 may transmit the humidity measurementsto a second device via wireless transmission.

FIG. 11 shows a concrete mixture 1120 in a form 1110 in accordance withanother embodiment. Sensor 100 is embedded under the surface of theconcrete. Sensor 100 may obtain measurements of the humidity of concretemixture 1120. Sensor 100 may transmit the humidity measurements to asecond device via wireless transmission.

In another embodiment, a sensor may be attached to a cap and placed on astandard test cylinder used to test specimens of concrete. FIG. 12 showsa test cylinder and a cap in accordance with an embodiment. Testcylinder 1250 may be a 4×8-inch or 6×12-inch test cylinder, for example.Test cylinder 1250 contains a specimen of concrete 1275. A cap 1220 isconstructed to fit onto test cylinder 1250. Sensor 100 is attached to aninterior surface 1223 of cap 1220. Sensor 100 is oriented so that hole120 faces downward.

Cap 1220 may be placed onto test cylinder 1250, as shown in FIG. 13. Cap1220 may form a seal when placed onto test cylinder 1250. After cap 1220has been placed onto test cylinder 1250, sensor 100 may obtainmeasurements of humidity. Because hole 120 faces downward, humiditygenerated by concrete 1275 may enter sensor 100 through hole 120. Asensor attached to a cap such as cap 1220 may be used in a similarmanner to obtain measurements of other characteristics of a concretemixture contained in a test cylinder, such as temperature, motion, etc.

Devices, systems, apparatus and methods for using a sensor deviceattached to a cap placed on a concrete test cylinder to obtainmeasurements of one or more characteristics of a concrete mixturecontained in the test cylinder are described, for example, in U.S.patent application Ser. No. 15/414,401, filed Jan. 24, 2017 and entitled“SYSTEMS, APPARATUS AND METHODS FOR OBTAINING MEASUREMENTS CONCERNINGTHE STRENGTH AND PERFORMANCE OF CONCRETE MIXTURES,” which is herebyincorporated by reference herein in its entirety and for all purposes.

In other embodiments, sensor 100 may be placed within a sensing device.FIG. 14 shows a cross-sectional view of components of a sensing devicein accordance with an embodiment. Sensing device 1400 includes a firstportion 1410 and a second portion 1420. First portion 1410 has ahemispherical shaped side 1413 and a flat side 1415. Flat side 1415 hasa hole 1440 that is approximately the same size as hole 120 of sensor100. Sensor 100 is disposed within first portion 1410, proximate theflat side 1415, such that hole 120 of sensor 100 is proximate hole 1440.A predetermined quantity of a substance such as lead is disposed insideof first portion 1410, on the side near hole 120 and hole 1440.

Second portion 1450 has a hemispherical shaped side 1453 and a flat side1455. Flat side 1455 has a notch 1475 on one side. A width W of notch1475 is greater than the width of hole 1440. A predetermined quantity ofa substance such as lead is disposed inside of second portion 1450, onthe side near notch 1475.

FIG. 15 shows a view of flat side 1455 of second portion 1450 of sensingdevice 1400 in accordance with the embodiment of FIG. 14. Notch 1475runs longitudinally across flat side 1455, defining a chord 1507.

First portion 1410 and second portion 1450 may be joined to form sensingdevice 1400. Specifically, flat side 1415 of first portion 1410 isattached to flat side 1455 of second portion 1450.

FIG. 16 shows a cross-sectional view of sensing device 1400 inaccordance with an embodiment. Sensing device 1400 has a spherical, orapproximately spherical, shape. Notch 1475 ensure that hole 1440 isexposed to the surrounding environment.

In accordance with an embodiment, sensing device 1400 may be inserted,or partially inserted, into a concrete mixture. While in the concretemixture, sensor 100 within sensing device 1400 may obtain measurementsof the humidity of the concrete mixture.

FIG. 17 shows sensing device 1400 embedded in a concrete mixture 1725 inaccordance with an embodiment. For example, sensing device 1400 may beinserted into a concrete mixture within a form at a construction site.The weight of material 1416 and material 1456 cause sensing device toorient itself with the notch 1475 on the underside of the device.Therefore, notch 1475 is embedded within the concrete mixture. A portion1728 of the concrete enters notch 1475. Humidity from the concretewithin notch 1475 enters hole 1440 of sensing device 1400, and entershole 120 of sensor 100. Humidity sensor 255 may therefore measure thehumidity of concrete 1725. Sensor 100 may transmit the humiditymeasurements via wireless transmission to a remote device.

In another embodiment, sensor 100 may be disposed within a sensingdevice having a different shape, such as a rectangular prism, atriangular prism, a cube, a disc, etc. FIG. 18 shows a sensing device1800 in accordance with another embodiment. Sensing device 1800 has acuboid shape (a rectangular prism with rounded edges). A hole 1820 isdisposed on one side of sensing device 1800. Hole 120 of sensor 100 isdisposed proximate to hole 1820 of sensing device 1800. In this manner,humidity of the surrounding environment may enter through hole 1820 andhole 120 and reach humidity sensor 255.

In accordance with an embodiment, data obtained by sensor 100 may betransmitted via a network to a processor. The processor analyzes thedata and generates a prediction relating to a characteristic of aconcrete mixture based on the data. For example, humidity measurementsobtained by sensor 100 may be used to generate a prediction of strengthor maturity of a concrete mixture. Data from multiple sensors may bereceived and used to generate multiple predictions.

FIG. 19 shows a communication system in accordance with an embodiment.Communication system 1900 includes a network 1905, which may include theInternet, for example, a data manager 1935, a prediction manager 1940,and a storage 1970. Communication system 1900 also includes a userdevice 1990, which may be a personal computer, a laptop device, a cellphone, a tablet device, etc.

Communication system 1900 also includes a local gateway 1983, which isconnected to network 1905. Local gateway 1983 may include a wirelessmodem, for example. Local gateway 1983 is located at a construction site1995, and is linked to a plurality of sensing devices 1950-A, 1950-B,1950-C, etc., which are disposed at various locations at theconstruction site. Each sensing device 1950 includes a sensor similar tosensor 100. Each sensing device 1950 may be similar to sensing device1400 described herein, for example.

Sensing devices 1950 are disposed at various sites at a constructionsite. For example, a sensing device 1950-A may be embedded in a firstconcrete form, sensing device 1950-B may be embedded in a secondconcrete form, etc. Using methods and apparatus similar to thosedescribed above, each sensing device 1950 obtains humidity measurementsrelated to a respective concrete mixture. Each sensing device 1950transmits measurement data to data manager 1935 via local gateway 1983and network 1905. For example, each sensing device 1950 may transmitmeasurement data wirelessly to local gateway 1983, which transmits themeasurement data to data manager 1935 via network 1905. Each sensingdevice 1950 may also transmit an identifier uniquely identifying itself.For example, an RFID tag embedded in each sensing device 1950 maytransmit identification information. Communication system 1900 mayinclude any number of sensing devices.

In one embodiment, multiple sensing devices 1950 may be located at asingle location (e.g., a single construction site). In anotherembodiment, multiple sensing devices 1950 may be located at multiplelocations (e.g., at multiple construction sites).

Communication system 1900 also includes a user device 1997, which may bea personal computer, laptop device, tablet device, cell phone, or otherprocessing device which is located at a construction site and used by atechnician at the site. User device 1997 may communicate with network1905, with local gateway 1983, with a sensing device 1950, and/or withother devices within communication system 1900.

Data manager 1935 receives humidity measurement data from one or moresensing devices 1950 and may analyze the measurement data. In theillustrative embodiment, data manager 1935 transmits the measurementdata to prediction manager 1940 (or otherwise makes the data availableto prediction manager 1940). Prediction manager 1940 may generatepredictions concerning the behavior of one or more concrete specimens.For example, prediction manager 1940 may receive humidity data fromsensing device 1950-A and, based on the measurement data, generatepredictions regarding the water-to-cementitious ratio, durability,strength, slump, maturity, etc., of the concrete mixture in whichsensing device 1950-A is located. In one embodiment, the measurementdata received by data manager 1935 is provided to a real-time model toproject setting behavior and strength for the entire batch of concrete.In another embodiment, the measurement data is continually subject tostatistical analysis to generate real-time projections, control charts,etc. Data manager 1935 may store the measurement data and/or theprediction data in storage 1970. For example, measurements and/orprediction data may be stored in a database. Other data structures maybe used to store measurement and/or prediction data.

In one embodiment, data manager 1935 may transmit measurement dataand/or prediction information relating to water-to-cementitious ratio,durability, strength, slump, maturity, etc. to a user device such asuser device 1990 or user device 1997 to enable a technician to accessand view the information. For example, user device 1990 and/or userdevice 1997 may display measurement data and/or prediction data on a webpage, or in another format.

In one embodiment, storage 1970 includes a cloud storage system. Dataobtained by a sensing device 1950 may be transmitted to and saved instorage 1970 in real-time. A cloud implementation such as thatillustrated by FIG. 19 may allow data from projects in multiple regionsor multiple countries to be auto-consolidated in a single database.

FIG. 20 is a flowchart of a method in accordance with an embodiment. Atstep 2010, a sensing device is embedded within a concrete mixture, thesensing device including a humidity sensor. At step 2020, a humiditymeasurement is received from the device via wireless transmission. Atstep 2030, a prediction of a characteristic of the concrete mixture isgenerated based on the humidity measurement.

While embodiments have been discussed herein in the context of theconcrete production and testing and construction industries, systems,methods, and apparatus described herein may be used in other fields andfor other uses, as well. For example, a sensor similar to sensor 100described herein, and/or a sensing device such as sensing device 1400described herein, may be used in an agricultural setting to determinethe humidity of soil. For example, a sensor may be placed on top of thesoil, or buried several inches or feet under the soil. FIG. 21A showssensor 100 disposed on the surface of soil 2115 in accordance with anembodiment. FIG. 21B shows sensor 100 embedded under the surface of soil2115 in accordance with another embodiment. In the manner describedherein, sensor 100 may obtain measurements of the humidity of soil 2115,and transmit the measurement data to a remote device via wirelesstransmission. A prediction of a characteristic of soil 2115 may then begenerated based on the measurement data.

In other embodiments, sensors and sensing devices described herein maybe used to analyze other substances including, without limitation,water, water mixtures, chemical products, paint, petroleum-basedsubstances, food products, etc.

In various embodiments, the method steps described herein, including themethod steps described in FIG. 20, may be performed in an orderdifferent from the particular order described or shown. In otherembodiments, other steps may be provided, or steps may be eliminated,from the described methods.

Systems, apparatus, and methods described herein may be implementedusing digital circuitry, or using one or more computers using well-knowncomputer processors, memory units, storage devices, computer software,and other components. Typically, a computer includes a processor forexecuting instructions and one or more memories for storing instructionsand data. A computer may also include, or be coupled to, one or moremass storage devices, such as one or more magnetic disks, internal harddisks and removable disks, magneto-optical disks, optical disks, etc.

Systems, apparatus, and methods described herein may be implementedusing computers operating in a client-server relationship. Typically, insuch a system, the client computers are located remotely from the servercomputer and interact via a network. The client-server relationship maybe defined and controlled by computer programs running on the respectiveclient and server computers.

Systems, apparatus, and methods described herein may be used within anetwork-based cloud computing system. In such a network-based cloudcomputing system, a server or another processor that is connected to anetwork communicates with one or more client computers via a network. Aclient computer may communicate with the server via a network browserapplication residing and operating on the client computer, for example.A client computer may store data on the server and access the data viathe network. A client computer may transmit requests for data, orrequests for online services, to the server via the network. The servermay perform requested services and provide data to the clientcomputer(s). The server may also transmit data adapted to cause a clientcomputer to perform a specified function, e.g., to perform acalculation, to display specified data on a screen, etc.

Systems, apparatus, and methods described herein may be implementedusing a computer program product tangibly embodied in an informationcarrier, e.g., in a non-transitory machine-readable storage device, forexecution by a programmable processor; and the method steps describedherein, including one or more of the steps of FIG. 20, may beimplemented using one or more computer programs that are executable bysuch a processor. A computer program is a set of computer programinstructions that can be used, directly or indirectly, in a computer toperform a certain activity or bring about a certain result. A computerprogram can be written in any form of programming language, includingcompiled or interpreted languages, and it can be deployed in any form,including as a stand-alone program or as a module, component,subroutine, or other unit suitable for use in a computing environment.

A high-level block diagram of an exemplary computer that may be used toimplement systems, apparatus and methods described herein is illustratedin FIG. 22. Computer 2200 includes a processor 2201 operatively coupledto a data storage device 2202 and a memory 2203. Processor 2201 controlsthe overall operation of computer 2200 by executing computer programinstructions that define such operations. The computer programinstructions may be stored in data storage device 2202, or othercomputer readable medium, and loaded into memory 2203 when execution ofthe computer program instructions is desired. Thus, the method steps ofFIG. 20 can be defined by the computer program instructions stored inmemory 2203 and/or data storage device 2202 and controlled by theprocessor 2201 executing the computer program instructions. For example,the computer program instructions can be implemented as computerexecutable code programmed by one skilled in the art to perform analgorithm defined by the method steps of FIG. 20. Accordingly, byexecuting the computer program instructions, the processor 2201 executesan algorithm defined by the method steps of FIG. 20. Computer 2200 alsoincludes one or more network interfaces 2204 for communicating withother devices via a network. Computer 2200 also includes one or moreinput/output devices 2205 that enable user interaction with computer2200 (e.g., display, keyboard, mouse, speakers, buttons, etc.).

Processor 2201 may include both general and special purposemicroprocessors, and may be the sole processor or one of multipleprocessors of computer 2200. Processor 2201 may include one or morecentral processing units (CPUs), for example. Processor 2201, datastorage device 2202, and/or memory 2203 may include, be supplemented by,or incorporated in, one or more application-specific integrated circuits(ASICs) and/or one or more field programmable gate arrays (FPGAs).

Data storage device 2202 and memory 2203 each include a tangiblenon-transitory computer readable storage medium. Data storage device2202, and memory 2203, may each include high-speed random access memory,such as dynamic random access memory (DRAM), static random access memory(SRAM), double data rate synchronous dynamic random access memory (DDRRAM), or other random access solid state memory devices, and may includenon-volatile memory, such as one or more magnetic disk storage devicessuch as internal hard disks and removable disks, magneto-optical diskstorage devices, optical disk storage devices, flash memory devices,semiconductor memory devices, such as erasable programmable read-onlymemory (EPROM), electrically erasable programmable read-only memory(EEPROM), compact disc read-only memory (CD-ROM), digital versatile discread-only memory (DVD-ROM) disks, or other non-volatile solid statestorage devices.

Input/output devices 2205 may include peripherals, such as a printer,scanner, display screen, etc. For example, input/output devices 2205 mayinclude a display device such as a cathode ray tube (CRT) or liquidcrystal display (LCD) monitor for displaying information to the user, akeyboard, and a pointing device such as a mouse or a trackball by whichthe user can provide input to computer 2200.

Any or all of the systems and apparatus discussed herein, includingsensor 100, sensing device 1400, data manager 1935, prediction module1940, storage 1970, local gateway 1983, user device 1990, and userdevice 1997, and components thereof, may be implemented using a computersuch as computer 2200.

One skilled in the art will recognize that an implementation of anactual computer or computer system may have other structures and maycontain other components as well, and that FIG. 22 is a high levelrepresentation of some of the components of such a computer forillustrative purposes.

In accordance with another embodiment, a sensor is embedded in a layerof concrete (e.g., within a concrete floor or other surface). A secondlayer of a selected material (e.g., rubber) is deposited on top of theconcrete layer. The second layer may be deposited on the concrete tofunction as a protective layer or for another reason. The sensor obtainsmeasurements of one or more characteristics of the concrete andtransmits the information. A second device receives the measurement dataand may predict a second characteristic of the concrete based on themeasurement data.

FIG. 23A is a flowchart of a method of determining one or morecharacteristics of concrete in accordance with an embodiment. At step2310, concrete is laid to create a floor or other surface. At step 2320,a sensor is embedded under the surface of the concrete at a selecteddepth. For example, the sensor may be embedded at a depth ofapproximately one inch. A sensor may be embedded at other depths. Atstep 2330, a coating of a selected material is added over the concrete.

FIG. 23B shows the construction of a concrete floor in accordance withan embodiment. Concrete layer 2310 is laid down. Sensor 2300 is embeddedin the concrete. Sensor 2300 may be similar to sensor 100 of FIG. 1 andFIG. 2, for example. A layer 2320 of a selected material is laid down ontop of the concrete layer 2310. For example layer 2320 may includerubber or another material.

At step 2340, the sensor obtains measurement data of one or moreselected characteristics of the concrete. In the illustrativeembodiment, sensor 2300 obtains measurement data pertaining to one ormore characteristics of the concrete in layer 2310. For example, sensor2300 may obtain data pertaining to temperature, humidity, salinity, pHlevels, sonic signals, conductivity, etc. At step 2350, the sensortransmits the measurement data. Sensor 2300 transmits the measurementdata wirelessly. At step 2360, a second device receives the measurementdata from the sensor. In the illustrative embodiment, a second device2350 receives the measurement data. As discussed elsewhere herein, themeasurement data may be used to predict one or more characteristics ofthe concrete in layer 2310.

The inventors have observed that use of sensor devices, such as sensor100 of FIG. 1 and FIG. 2, to obtain data relating to a concrete mixtureis sometimes complicated by the difficulty of determining when toactivate the sensor device (i.e., when to activate the various sensorsof the sensor device so that the sensors begin to generate datapertaining to characteristics of the concrete and transmit themeasurement data) and the further difficulty of actually activating thesensor device at a desired time. On the one hand, it is undesirable toactivate the sensor device before the sensor device has been embedded inthe concrete. On the other hand, it is undesirable to activate thesensor device long after the sensor device has been embedded in theconcrete. Ideally, the sensor device should be activated at the momentthe sensor device is embedded in the concrete mixture.

The inventors have further observed that a sensor device typicallyexperiences a spike in humidity when first embedded in a concretemixture. The humidity within a concrete mixture is typicallysignificantly higher than the humidity of the outside environment. Theinventors have determined that this difference can be utilized todetermine when to activate a sensor device.

Thus, in accordance with an embodiment, a sensor device includes ahousing and a plurality of sensors disposed in the housing. Theplurality of sensors include a humidity sensor and one or more secondsensors adapted to obtain measurements of selected characteristics of aconcrete mixture, such as temperature, salinity, pH levels, sonicsignals, motion, elevation, acceleration, conductivity, etc. Forexample, the plurality of sensors may include one or more of thefollowing: a temperature sensor, a salinity sensor, a conductivitysensor, a motion sensor, a pH sensor, an acceleration sensor, a sonicsensor, etc. The housing includes an opening adapted to permit humidityto enter the housing but prevent liquid (and concrete) from entering thehousing. The opening may be a hole in the housing, for example. Forexample, the dimensions of the hole may be sufficiently small so thatthe surface tension of water prevents water and concrete from passingthrough the hole. For example, the hole may have a width of onemillimeter or smaller. The humidity sensor within the sensor device isdisposed proximate the hole.

FIG. 24A shows a sensor device 2400 in accordance with an embodiment.Sensor device 2400 includes a housing 2410. Housing 2410 includes anopening. In the illustrative embodiment, the opening is a hole 2420.Hole 2420 allows water vapor to pass through; however, the diameter ofhole 2420 is sufficiently small so that water and concrete cannot passthrough the hole. For example, the hole may have a width of onemillimeter or smaller. For example, hole 2420 may have a diameter ofbetween 0.5 millimeters and 1.0 millimeter.

FIG. 24B shows components of the sensor device of FIG. 2400. Sensordevice 2400 includes an upper portion 2406 and a lower portion 2408 ofhousing 2410. Sensor device 2400 also includes a printed circuit board(PCB) 2440. PCB 2440 includes a plurality of elements 2448, which mayinclude circuit components such as resistors, capacitors, amplifiers,etc., and/or one or more sensors adapted to obtain measurements relatingto one or more characteristics such as temperature, salinity,conductivity, motion, etc. For example, PCB 2440 may include one or moreof the following: a temperature sensor, a salinity sensor, aconductivity sensor, a motion sensor, a pH sensor, an accelerationsensor, a sonic sensor, etc. In one embodiment, at least one of elements2448 is a processor adapted to receive measurement data and analyze themeasurement data. PCB 2440 also includes a transceiver 2449, which mayinclude an antenna capable of sending and receiving data via wirelesscommunication, for example. In another embodiment, PCB 2440 includes atransmitter. PCB may also include a battery. PCB 2440 also includes ahumidity sensor 2455. When housing 2410 is closed, humidity sensor 2455is located under or proximate hole 2420 such that humidity (water vapor)that enters through hole 2420 is detected by humidity sensor 2455.

PCB 2440 fits into bottom portion 2408. Upper portion 2406 fits ontolower portion 2408, creating a protective seal.

In another embodiment, a sensor device includes a housing that includesan upper portion and a lower portion (such as upper portion 2406 andlower portion 2408). The upper portion and lower portion are adapted toengage and create a partial seal. For example, the upper portion mayhave first threads that engage with second threads of the lower portion.However, the connection between the upper and lower portions is not aseal. An opening exists between the upper and lower portions that allowswater vapor to pass between the exterior and interior of the sensordevice but does not allow liquid to pass between the exterior andinterior.

FIG. 25 is a flowchart of a method of activating a sensor device inaccordance with an embodiment. At step 2510, concrete is laid in a formto create a desired structure. FIG. 26A shows a construction site 2610in accordance with an embodiment. Site 2610 includes a concrete mixingtruck 2612 having a drum 2613. Concrete 2614 is poured down a chute 2615and deposited in a form 2616. The form 2616 thus contains concrete 2618forming a desired structure.

In the illustrative embodiment, a technician has access to one or moresensor devices that are similar to sensor device 2400 shown in FIG. 24B.Each of these sensor devices is deactivated. When a sensor device isdeactivated, any sensors within the sensor device capable of generatingdata pertaining to various characteristics of concrete (e.g.,temperature, salinity, pH, conductivity, etc.) are not activated and donot generate measurement data. The transmitter (e.g., transmitter 2449)within the sensor device does not transmit data. However, even when thesensor device is deactivated, the humidity sensor 2455 continues tofunction and generates measurements of humidity.

In another embodiment, when a sensor device is deactivated, thetransceiver (e.g., transceiver 2449) is active and transmits thehumidity measurements generated by humidity sensor 2445 to a remotedevice (such as data manager 1935). The remote device may be adapted torespond to the humidity measurements and activate the sensor devicefully based on the humidity measurements received.

Returning to FIG. 25, at step 2520, a sensor device is inserted into theconcrete. In the illustrative embodiment of FIG. 26A, a technician 2623at the construction site drops or throws a sensor device 2625 into theconcrete 2618 in form 2616. For example, sensor device 2625 may be asensor device similar to sensor device 2400 of FIG. 24B. Prior to themoment when the technician picks up sensor device 2625 and throws itinto concrete 2618, the sensor device is deactivated. As seen in FIG.26A, a plurality of sensor devices 2627 may be inserted into concrete2618.

Referring to FIG. 24B, before the sensor device 2625 is inserted intothe concrete 2618, water vapor enters the sensor device (e.g., throughopening or hole 2420). Consequently, the humidity sensor in the sensordevice (e.g., humidity sensor 2455 of FIG. 24B) detects a first level ofhumidity representing the humidity of the surrounding environment.

After sensor device 2625 is inserted (dropped, thrown, etc.) intoconcrete 2618, water vapor within the concrete enters into sensor device2625 (through the opening or hole 2420). Consequently, humidity sensor2455 of sensor device 2625 detects the humidity of the concrete.Typically, the humidity of the concrete is higher than the humidity ofthe surrounding environment.

Accordingly, at step 2530, a spike in humidity is detected. For example,a processor 2448 on PCB 2440 (in sensor device 2625) may detect a spikein humidity based on predetermined criteria. For example, humiditysensor 2455 may transmit humidity measurements to processor 2448 on PCB2440, and the processor 2448 may determine that the humidity hasexperienced a spike defined as a change from a first predetermined levelto a second predetermined level; alternatively a spike in humidity maybe defined as any change in humidity that exceeds a predeterminedamount. Other methods may be used to detect a spike in humidity.

FIG. 26B shows a graph illustrating humidity measurements obtained by asensor device in accordance with an embodiment. Specifically, graph 2600shows humidity measurements obtained by sensor device 2625 versus time.Referring to graph 2600, region 2605 represents the time before thesensor device is inserted into the concrete mixture. During this time,the humidity sensor 2455 detects the humidity of the surroundingenvironment, which has a first level of humidity (which may varyslightly). At the moment the sensor device is inserted into concrete2618, the humidity (water vapor) of the concrete enters opening 2420 andis detected by humidity sensor 2455. Because the humidity of concrete2618 is significantly higher than the humidity of the surrounding air,humidity sensor 2455 detects a spike in humidity when it is insertedinto concrete 2618. As a result, the humidity measurements rise to apeak 2630 and then decrease slightly to a second level that issignificantly higher than those associated with region 2605. The region2608 represents the time after the sensor device was inserted into theconcrete mixture.

In one embodiment, a time associated with the spike in humidity detectedby the sensor device may be determined based on the humiditymeasurements. This determined time may be used as time zero (T=0) torepresent the moment when the sensor device was inserted into theconcrete mixture. Mathematical methods of determining a starting timefor a significant change in humidity measurements are known. Forexample, the data may be analyzed and an inflection point in the datamay be determined. Alternatively, a curve associated with the humiditymeasurements may be examined and a point at which the slope of the curveexceeds a predetermined level may be selected as time zero. Othermethods may be used. In the illustrative embodiment of FIG. 26B, a timeT (2635) is determined based on the spike in the humidity measurements.

Referring again to FIG. 25, at step 2540, the sensor device is activatedin response to the spike in the humidity measurements. In theillustrative embodiment, processor 2448 on PCB 2440 activates the sensordevice by activating other sensors and components on PCB 2440 inresponse to the detection of the humidity spike. In another embodiment,a remote device, such as data manager 1935 (communicating with thesensor device via the Internet), may activate the sensor device.

Thus, the sensor device 2625 is activated when humidity sensor 2455detects the spike in humidity. Specifically, other components andsensors of the sensor device are activated. For example, other sensors(such as sensors capable of detecting temperature, salinity, pH,conductivity, etc.) are activated and begin to measure variouscharacteristics of the concrete mixture. Transceiver 2449 begins totransmit the measurement data.

The inventors have further observed that a sonic signal detected by asensor device typically experiences a drop in magnitude when the sensordevice is first inserted into a wet concrete mixture. Sonic signals(sound waves) typically travel more easily through air than through wetconcrete. Thus, if a sensor begins in the surrounding air (e.g., thesensor is held by a technician) and then is inserted into a wet concretemixture, any sonic sensor on the sensor device that is monitoring sonicsignals typically experiences signal loss starting at the moment thesensor device is inserted into the wet concrete mixture. The inventorshave determined that this signal loss can be utilized to determine whento activate a sensor device.

FIG. 26C is a flowchart showing a method of activating components of asensor device in accordance with another embodiment. At step 2650, asonic signal (e.g., a sound wave) received by a sensor device isexamined. Referring again to the illustrative embodiment of FIG. 26A,suppose that sensor device 2625 includes a sonic sensor adapted todetect sonic signals (sound waves). A processor of sensor device 2625monitors and analyzes the sonic signals received. For example, sensordevice 2625 may include elements similar to elements 2448 on PCB 2440;the elements may include a sonic sensor and a processor. Alternatively,the sonic signals detected may be transmitted wirelessly to a remoteprocessor adapted to analyze the sonic signals.

FIG. 26D shows a graph 2670 of a sonic signal 2675 that may be detectedby a sonic sensor on a sensor device in accordance with an embodiment.In the illustrative embodiment, the sonic sensor begins to detect sonicsignals at time T0. The sensor device is held by a technician at time T0until about time T1. During the period P1 between time T0 and time T1,the sonic signal 2675 has a magnitude (in decibels) around a firstinitial level, reflecting the sonic signals (including background noise,talking, and any other noises) in the air surrounding the technician.

Suppose now that the technician inserts the sensor device into aconcrete mixture at about time T1. At step 2652, a change in thestrength of the sonic signal (sound wave) from a first level to a secondlevel is detected. Specifically, after the sensor is embedded in theconcrete mixture, the sonic signal detected by the sonic sensor on thesensor device decreases in strength. Thus, referring to graph 2670, thestrength of the sonic signal 2675 decreases after time T1 (associatedwith point 2683) to a second level. The sonic signal displays a signalstrength having a second level (which is lower than the first level)between approximately T1 and approximately time T2. The processor of thesensor device 2625 determines that a decrease in the strength of thesonic signal has been detected.

At step 2654, one or more components of the sensor device are activatedin response to the change in the strength of the sonic signal. Inresponse to the determination that the strength of the sonic signal hasdecreased from the first level to the second level, one or morecomponents of the sensor device 2625 are activated. For example, one ormore of a temperature sensor, a humidity sensor, a salinity sensor, anaccelerometer, a pH sensor, a conductivity sensor, etc., on sensordevice 2625 may be activated.

As the concrete mixture dries, the properties of the concrete mixturemay change; for example, the dry concrete mixture may transmit soundsignals more easily than the wet concrete. As a result, the sonic sensoron the sensor device 2625 may detect an increase in the strength of thesonic signals as the concrete sets. In the illustrative embodiment ofFIG. 26D, the strength of sonic signal 2675 increases starting at abouttime T2 (associated with point 2696 on graph 2670). The strength ofsonic signal 2675 rises to a third level (different from the secondlevel). One or more components of the sensor device 2625 may beactivated based on the detection of the signal from the second level tothe third level.

FIGS. 27A-27C show components of a sensor device in accordance withanother embodiment. As shown in FIG. 27A, sensor device 2700 includes ahousing that includes an upper portion 2707 and a lower portion 2705.Upper portion 2707 and lower portion 2705 may be formed from plastic,metal, or other material. Sensor device 2700 also includes a waterprooflayer 2715, a support 2722, and a sensor component 2730.

Upper portion 2707 of housing includes a plurality of holes 2709. In theillustrative embodiment of FIG. 27A, upper portion 2707 includesseventy-two holes arranged in an 8×9 array. In other embodiments, upperportion 2707 of the housing may include any number of holes arranged inany configuration.

Each hole may be any size. For example, each hole may between 0.5 and6.0 millimeters wide. The holes are adapted to allow humidity to passthrough from the exterior of sensor device 2700 to the interior of thesensor device. In some embodiments, the holes may allow liquid and/orconcrete to pass through. In other embodiments, the holes do not allowliquid or concrete to pass through.

Waterproof layer 2715 is made of a waterproof, breathable material thatallows humidity (water vapor) to pass through the layer but does notallow liquid or concrete to pass through. For example, waterproof layer2715 may be made waterproof, breathable fabric membrane such as Gore-Texor other similar material.

Sensor component 2730 includes one or more sensors adapted to measureone or more characteristics of a surrounding material (such as concrete,water, etc.) Sensor component 2730 may be, for example, a printedcircuit board (PCB) containing circuit components such as resistors,capacitors, amplifiers, etc., and/or one or more sensors adapted toobtain measurements relating to one or more characteristics such astemperature, humidity, salinity, conductivity, motion, etc. Sensorcomponent 2730 may also include a processor. Sensor component 2730 mayalso include a transceiver, or may include a transmitter and a receiver.Sensor component 2730 may also include a battery. Alternatively, abattery or other power source may be disposed elsewhere in sensor device2700.

Support 2722 is disposed between sensor component 2730 and waterprooflayer 2715. Support 2722 separates waterproof layer 2715 from sensorcomponent 2730 and thereby protects the sensors (and other electronics)of sensor component 2730 from water, liquids, concrete, etc. that may beproximate waterproof layer 2715. Thus support 2722 may maintain apredetermined distance between waterproof layer 2715 and sensorcomponent 2730.

In the illustrative embodiment, sensor device 2700 is assembled byfitting sensor component 2730 into lower portion 2705 of the housing,and placing support 2722 above sensor component 2730, as illustrated inFIGS. 27A and 27B. Waterproof layer 2715 is placed above support 2722,and upper portion 2707 is fitted over lower portion 2705, as illustratedin FIGS. 27B and 27C. Upper portion 2707 and lower portion 2705 may forma seal when fitted together. FIG. 27C shows sensor device 2700 in afully assembled state.

In accordance with an embodiment, sensor device 2700 may be attached toa cap adapted to fit onto a standard concrete test cylinder. FIG. 28shows sensor device 2700 and a cap 2800 adapted to be placed onto astandard concrete test cylinder. For example, sensor device 2700 may beattached to an interior surface of cap 2800 in the manner shown in FIG.12. In the manner described herein, sensor device 2700 may then obtainmeasurements relating to one or more characteristics of the concretemixture in the test cylinder. Sensor device 2700 may transmit themeasurement data wirelessly.

It has been observed that certain components of a sensor device such asthose described herein can sometimes suffer damage if the sensor deviceis dropped, thrown, or otherwise experiences a rapid or jarringmovement. In particular, it has been observed that if a sensor device isthrown or dropped into a concrete mixture at a construction site, thebattery within the sensor device may be damaged by the associated rapidmovements. Therefore, a need exists for a sensor device design thatprotects a battery from rapid, jarring movements that may occur when thesensor device is thrown, dropped, etc.

FIGS. 29A-29D show a sensor device in accordance with anotherembodiment. FIG. 29A shows components of a sensor device 2900. Sensordevice 2900 includes a housing that includes an upper portion 2906 and alower portion 2908. Upper portion 2906 may include one or more holesthat allow water vapor (but not liquid or concrete) to pass through.Sensor device 2900 also includes a sensor component 2912 which includesone or more sensors. For example, sensor component 2912 may be, forexample, a printed circuit board (PCB) containing circuit componentssuch as resistors, capacitors, amplifiers, etc., and/or one or moresensors 2914 adapted to obtain measurements relating to one or morecharacteristics such as temperature, salinity, conductivity, motion,etc. For example, the sensor component 2912 may include one or more ofthe following: a temperature sensor, an accelerometer, a pH sensor, aninductance sensor, an impedance or resistivity sensor, a sonic sensor, apressure sensor, a conductivity sensor, a salinity sensor, a humiditysensor, or an elevation sensor. One example of the temperature sensor isa miniature-sized temperature logger “SMARTBUTTON” (ACR SYSTEMS INC.).In one embodiment, a salinity sensor may include a chloride ionelectrode, for example. Sensor component 2912 may also include atransceiver, or may include a transmitter and a receiver.

Sensor component 2917 also includes a hole 2917 in a selected location.In the illustrative embodiment of FIGS. 29A-29D, hole 2917 is proximatea corner of sensor component 2912; however, in other embodiments, hole2917 may be at a different location on sensor component 2912.

Sensor device 2900 also includes a battery 2925 adapted to provide powerto various sensors and other electronic elements of sensor component2912.

Hole 2917 of sensor component 2912 is adapted to receive battery 2925.Preferably, the size and shape of hole 2917 are selected such thatbattery 2925 fits snugly through hole 2917 with little or no spacebetween the battery and the edge of the hole.

Lower portion 2908 of the housing includes a casing 2934 disposed in aselected location. While in the illustrative embodiment, casing 2934 isdisposed in a corner of the lower portion 2908, in other embodiments,casing 2934 may be located at any selected location of the housing.Casing 2934 includes a solid peripheral portion 2935 and a centralcavity 2936. Cavity 2936 is adapted to receive and hold at least aportion of battery 2925. Preferably, the size and shape of cavity 2936are selected such that battery 2925 fits snugly into cavity 2936 withlittle or no space between the battery and the side of cavity 2936, toensure that battery 2925 does not move or shake when placed in thecavity.

Referring to FIGS. 29B-29D, sensor device 2900 is assembled by placingbattery 2925 into cavity 2936. FIG. 29B shows components of sensordevice 2900 after battery 2935 has been placed into cavity 2936. Sensorcomponent 2912 is then placed into lower portion 2908 of the housing.Battery 2925 passes through hole 2917, allowing sensor component 2912 tofit into lower portion 2908 of the housing. FIG. 29C shows sensor device2900 after sensor component 2912 has been placed into lower portion 2908of the housing. Batter 2925 is visible and may protrude from hole 2917of sensor component 2912.

Upper portion 2906 of the housing is then secured onto lower portion2908. Upper portion 2906 and lower portion 2908 may form a seal whenfitted together. FIG. 29D shows sensor device 2900 in a fully assembledstate.

Advantageously, the placement of battery 2925 within cavity 2936 andhole 2917 secures battery 2925 in place and prevents battery 2925 frommoving within sensor device 2900 if sensor device 2900 is moved. Thisdesign advantageously protects the battery from being damaged if sensordevice 2900 is dropped, thrown, or is otherwise moved in a jarringmanner.

FIGS. 30A-30C show components of a sensor device in accordance withanother embodiment. As shown in FIG. 30A, sensor device 3000 includes ahousing that includes an upper portion 3007 and a lower portion 3005.Upper portion 3007 and lower portion 3005 may be formed from plastic,metal, or other material. Sensor device 3000 also includes a waterprooflayer 3015, a support 3022, and a sensor component 3030.

Upper portion 3007 of housing does not include any holes. Therefore,upper portion 3007 of the housing does not allow humidity to passthrough from the exterior of sensor device 3000 to the interior of thesensor device.

Lower portion 3005 includes a single hole 3075 that allows humidity(water vapor) to pass into the interior of sensor device 3000 but doesnot allow water, concrete, or other liquids to enter. For example, hole3075 may be a hole having a diameter of between about 1.0 millimetersand 3.0 millimeters, preferably about 2.0 millimeters. Other diametersmay be used.

Sensor component 3030 includes one or more sensors adapted to measureone or more characteristics of a surrounding material (such as concrete,water, etc.) Sensor component 3030 may be, for example, a printedcircuit board (PCB) containing circuit components such as resistors,capacitors, amplifiers, etc., and/or one or more sensors adapted toobtain measurements relating to one or more characteristics such astemperature, humidity, salinity, conductivity, motion, etc. Sensorcomponent 3030 may also include a processor. Sensor component 3030 mayalso include a transceiver, or may include a transmitter and a receiver.Sensor component 3030 may also include a battery. Alternatively, abattery or other power source may be disposed elsewhere in sensor device3000.

Waterproof layer 3015 is made of a waterproof, breathable material thatallows humidity (water vapor) to pass through the layer but does notallow liquid or concrete to pass through. For example, waterproof layer3015 may be made waterproof, breathable fabric membrane such as Gore-Texor other similar material.

Support 3022 is disposed between sensor component 3030 and waterprooflayer 3015. Support 3022 separates waterproof layer 3015 from sensorcomponent 3030 and thereby protects the sensors (and other electronics)of sensor component 3030 from water, liquids, concrete, etc. that may beproximate waterproof layer 3015. Thus support 3022 may maintain apredetermined distance between waterproof layer 3015 and sensorcomponent 3030.

In the illustrative embodiment, sensor device 3000 is assembled byfitting waterproof layer 3015 and support 3022 into lower portion 3005of the housing, as illustrated in FIGS. 30A-30B. Sensor component 3030is then placed above support 3022, and upper portion 3007 is fitted overlower portion 3005, as illustrated in FIGS. 30B and 30C. Upper portion3007 and lower portion 3005 may form a seal when fitted together. FIG.30C shows sensor device 3000 in a fully assembled state.

FIGS. 31A-31D show components of a sensor device in accordance withanother embodiment. As shown in FIG. 31A, sensor device 3100 includes ahousing that includes an upper portion 3107 and a lower portion 3105.Upper portion 3107 and lower portion 3105 may be formed from plastic,metal, or other material. Sensor device 3100 also includes a waterprooflayer 3115, a support 3122, and a sensor component 3130.

Upper portion 3107 of housing does not include any holes. Therefore,upper portion 3107 of the housing does not allow humidity to passthrough from the exterior of sensor device 3100 to the interior of thesensor device.

Lower portion 3105 includes an array of holes 3180. Holes 3180 allowliquid and humidity (water vapor) to pass into the interior of sensordevice 3100. An array of any size may be used. For example, a 5×5 arrayof holes, a 6×6 array of holes, a 5×6 array of holes, or otherconfiguration may be used. In one embodiment, each hole 3180 may be asquare or rectangular hole having sides of length between 5.5millimeters and 6.5 millimeters, preferably a square hole having sidesof length 6.1 millimeters. Other shapes and dimensions may be used.Lower portion 3105 may include an array having holes of uniform shapeand size, or may have an array with holes of different shapes and sizes.For example, holes at the corners and around the edges of a 6×5 arraymay be smaller and/or have shapes that are different from the sizes andshapes of the holes in the center of the array.

Sensor component 3130 includes one or more sensors adapted to measureone or more characteristics of a surrounding material (such as concrete,water, etc.) Sensor component 3130 may be, for example, a printedcircuit board (PCB) containing circuit components such as resistors,capacitors, amplifiers, etc., and/or one or more sensors adapted toobtain measurements relating to one or more characteristics such astemperature, humidity, salinity, conductivity, motion, sound, etc.Sensor component 3130 may also include a processor. Sensor component3130 may also include a transceiver, or may include a transmitter and areceiver. Sensor component 3130 may also include a battery.Alternatively, a battery or other power source may be disposed elsewherein sensor device 3100.

Waterproof layer 3115 is made of a waterproof, breathable material thatallows humidity (water vapor) to pass through the layer but does notallow liquid or concrete to pass through. For example, waterproof layer3115 may be made waterproof, breathable fabric membrane such as Gore-Texor other similar material.

Support 3122 is disposed between sensor component 3130 and waterprooflayer 3115. Support 3122 separates waterproof layer 3115 from sensorcomponent 3130 and thereby protects the sensors (and other electronics)of sensor component 3130 from water, liquids, concrete, etc. that may beproximate waterproof layer 3115. Thus support 3122 may maintain apredetermined distance between waterproof layer 3115 and sensorcomponent 3130.

In the illustrative embodiment, sensor device 3100 is assembled byfitting waterproof layer 3115 and support 3122 into lower portion 3105of the housing, as illustrated in FIGS. 30A and 30C. Sensor component3130 is then placed above support 3122, and upper portion 3107 is fittedover lower portion 3105, as illustrated in FIGS. 31C and 31D. Upperportion 3107 and lower portion 3105 may form a seal when fittedtogether. FIG. 31D shows sensor device 3100 in a fully assembled state.Lower portion 3105 and holes 3180 is visible in FIG. 31D.

In one embodiment, sensor device 3100 may be attached to an internalsurface of a cap adapted to be placed onto a standard test cylinder.FIG. 32A shows a cap and a sensor device in accordance with anembodiment. Cap 3200 is adapted to fit onto the top of a standardconcrete test cylinder. Sensor 3100 is attached to an internal surfaceof cap 3200. Cap 3200 is then placed onto a test cylinder that containsconcrete. FIG. 32B shows a cap and a test cylinder in accordance with anembodiment. Sensor device 3100 is attached to the internal surface ofthe cap 3200. Cap 3200 is fitted onto a test cylinder 3220, which holdsa specimen of a concrete mixture 3246. As concrete mixture 3246 dries,sensor device 3100 obtains measurements relating to one or morecharacteristics of the concrete. For example, sensor device 3100 mayobtain data relating to humidity, temperature, etc. Measurement data maybe transmitted wirelessly by the sensor device.

In another embodiment, sensor device 3100 may be inserted into aconcrete mixture. FIG. 33A shows a form holding a concrete mixture inaccordance with an embodiment. Form 3310 holds a concrete mixture 3346.Sensor device 3100 may be dropped or inserted into concrete mixture3346. FIG. 33B shows form 3310, concrete mixture 3346, and sensor device3100 embedded in the concrete mixture in accordance with an embodiment.Sensor device 3100 may obtains measurements relating to one or morecharacteristics of concrete mixture 3346. Measurement data may betransmitted wirelessly by the sensor device.

In one embodiment, components of a sensor device (such as any of thosedescribed herein) may be formed of a thermosetting resin or athermoplastic.

In one embodiment, a sensor device (such as any of those describedherein) may have a housing with a square or rectangular shape, with afirst side having a length between about 1.5 inch and about 2.0 inches,a second side having a length between about 1.5 inch and about 2.0inches, and a thickness between about one-eight inch and one-half inch.In a preferred embodiment, a sensor device has a housing with a squareshape with sides having a length of about one and three-fourths (1.75)inches, and a thickness of about three-sixteenth ( 3/16) inches.

It has been observed that when a sensor device with a transmitter (e.g.,antenna) is embedded in a concrete mixture at a depth less than aboutsix (6) inches, the signal transmitted by the sensor device is readilydetectable by a remote receiver. However, it has been observed that insome environments, and in some concrete mixtures, when a sensor deviceis embedded in a concrete mixture at a depth greater than about six (6)inches, the signal strength may rapidly decrease and become undetectableto a receiver outside the concrete mixture. Therefore, there is a needfor devices, systems, and methods that enable a sensor device embeddedin a concrete mixture at a depth of greater than six inches to be ableto transmit a signal that can be detected by a receiver located outsidethe concrete mixture.

FIG. 34A shows components of a sensor device in accordance with anotherembodiment. A sensor device 3400 includes a housing that includes anupper portion 3407 and a lower portion 3405. Upper portion 3407 andlower portion 3405 may be formed from plastic, metal, or other material.Sensor device 3400 also includes a waterproof layer 3415, a support3422, and a sensor component 3430.

Upper portion 3407 of housing does not include any holes. Therefore,upper portion 3407 of the housing does not allow humidity to passthrough from the exterior of sensor device 3400 to the interior of thesensor device.

Lower portion 3405 includes a single hole 3475 that allows humidity(water vapor) to pass into the interior of sensor device 3400 but doesnot allow water, concrete, or other liquids to enter. For example, hole3475 may be a hole having a diameter of between about 1.0 millimetersand 3.0 millimeters, preferably about 2.0 millimeters. Other diametersmay be used.

Sensor component 3430 includes one or more sensors 3432 adapted tomeasure one or more characteristics of a surrounding material (such asconcrete, water, etc.) Sensor component 3430 may be, for example, aprinted circuit board (PCB) containing circuit components such asresistors, capacitors, amplifiers, etc., and/or one or more sensorsadapted to obtain measurements relating to one or more characteristicssuch as temperature, humidity, salinity, conductivity, motion, etc.Sensor component 3430 may also include a processor. Sensor component3430 includes an antenna 3433 adapted to transmit signals, for example,in the form of electromagnetic radiation having a selected frequency.Sensor component 3430 may also include a receiver and/or a transceiver.For example, antenna 3433 may also be adapted to function as a receiver.Sensor component 3430 may also include a battery. Alternatively, abattery or other power source may be disposed elsewhere in sensor device3400.

Waterproof layer 3415 is made of a waterproof, breathable material thatallows humidity (water vapor) to pass through the layer but does notallow liquid or concrete to pass through. For example, waterproof layer3415 may be made waterproof, breathable fabric membrane such as Gore-Texor other similar material.

Support 3422 is disposed between sensor component 3430 and waterprooflayer 3415. Support 3422 separates waterproof layer 3415 from sensorcomponent 3430 and thereby protects the sensors (and other electronics)of sensor component 3430 from water, liquids, concrete, etc. that may beproximate waterproof layer 3415. Thus support 3422 may maintain apredetermined distance between waterproof layer 3415 and sensorcomponent 3430.

In accordance with an embodiment, a conductive wire is wound aroundsensor device 3400 to form coil having a plurality of loops. FIG. 34Bshows sensor device 3400 and a wire 3480 wound around the device,forming a plurality of loops 3485, in accordance with an embodiment.Wire 3480 may be formed of any conductive material, such as metal. Wire3480 may be insulated by a nonconductive material. In anotherembodiment, wire 3480 is not insulated. In one embodiment, wire 3480 iswound around the sensor device to form at least five (5) loops.

When the antenna 3433 within sensor device 3400 transmits a signal bygenerating electromagnetic radiation, loops 3485 function as aninduction coil, and a current is generated in wire 3480 (due toelectromagnetic induction). In particular, when antenna 3433 (withinsensor device 3400) transmits a first signal in the form ofelectromagnetic radiation, an electrical current related to the firstsignal is generated within wire 3480. Wire 3480 may therefore serve asan antenna to transmit communication signals from sensor device 3400.

In accordance with an embodiment, the ends of wire 3480 are twistedtogether and connected to form a circuit. The twisted wire is used as anantenna to boost and/or transmit the signal generated by the antenna3433 in sensor 3400. FIG. 34C shows sensor device 3400 and a coil havinga plurality of loops 3485 in accordance with an embodiment. Two ends3480-A and 3480-B of wire 3480 are twisted together to form a twistedwire 3490. The ends if the wire are connected at connection 3495,forming a circuit.

FIG. 35 shows a form containing a concrete mixture in accordance with anembodiment. Concrete mixture 3520 has a depth greater than three (3)feet. Sensor device 3400, with coil loops 3485 is embedded in concretemixture 3520 at a depth of three (3) feet. Twisted wire 3490 ispositioned so that it extends from the sensor device to the surface ofconcrete mixture 3520. A portion 3550 of twisted wire 3490 projectsabove the surface of the concrete mixture and is exposed to thesurrounding environment.

In accordance with an embodiment, sensor device 3400 obtainsmeasurements of selected characteristics of concrete mixture 3520 (suchas temperature, humidity, etc.) and transmits a first electromagneticsignal representing the measurement data, via antenna 3433 (withinsensor device 3400). Coil loops 3485 function as an inductive coil andgenerate an electrical current related to the first signal. The twistedwire 3490 operates as an antenna and transmits a second electromagneticsignal based on the first signal; the second signal may be received by aremote receiver and provided to a processor for storage and/or analysis.

It has also been observed that a sensor device with an external wirecoil and antenna, such as that shown in FIG. 34C may be used to measurethe purity level of water and other liquids. For example, in oneembodiment, a sensor device includes a wire coil and antenna formed froma metal wire with no insulation. The sensor device is placed in a bodyof water (or other liquid) and the twisted wire antenna is positioned sothat a portion of the antenna extends above the surface of the water.The sensor device measures one or more characteristics of the water (orother liquid) and transmits the measurement data via an antenna withinthe sensor device. A current is induced in the metal wire coil and anelectromagnetic signal related to the current is transmitted via theportion of the twisted wire antenna that is exposed above the surface ofthe water. It has been observed that the strength of the signaltransmitted via the twisted wire antenna varies depending on the levelof impurities in the water. In particular, it has been observed that asignal having a higher strength is produced when the level of impuritiesin the water is low, and that a signal having lower strength (or nosignal at all) is transmitted when the level of impurities in the wateris high.

FIG. 36 shows a container of water 3600 holding water 3630 in accordancewith an embodiment. In other embodiments, other types of liquids may beused. Sensor device 3400 is positioned in the water 3630. A wire 3480 iswrapped around sensor device 3400 to form a coil having a plurality ofloops. The ends of wire 3480 are twisted to form an antenna; a portion3650 of antenna 3490 extends above the surface of water 3630. Wire 3480is a metal wire with no insulation. Other conductive materials may beused. As sensor device 3400 transmits measurement data, an electriccurrent is generated in the wire coil surrounding sensor device. Theelectric current is related to the signal produced by the sensor device,and produces an electromagnetic signal which is transmitted via antenna3490 to convey the measurement data. Specifically, portion 3650 ofantenna 3490 transmits the signal.

In one embodiment, the strength of the signal produced by antenna 3490is measured and used to determine a level of impurities in water 3630.For example, if little or no signal is produced by antenna 3490, it maybe determined that the level of impurities is high. If the strength ofthe signal is high, it may be determined that the level of impurities inwater 3630 is low.

Thus, in one embodiment, a method is provided. A sensor with an externalwire coil and antenna is submerged in a body of water. A portion of thewire antenna is exposed above the surface of the water. The sensordevice generates a first electromagnetic signal. A current is generatedin the wire coil due to electromagnetic induction. A secondelectromagnetic signal is transmitted by the wire antenna. The secondelectromagnetic signal generated is transmitted to a processor. Theprocessor may analyze the strength of the second signal and determine alevel of impurities in the water based on the strength of the secondsignal.

In accordance with another embodiment, a sensor device includes ahousing and at least one wire extending from the housing. The sensordevice is embedded in a concrete mixture. The sensor device obtainsmeasurements of one or more characteristics of the concrete mixture,such as temperature, humidity, etc.

The at least one wire functions as an antenna. A signal containing theinformation relating to the measurements of the one or morecharacteristics is transmitted via the wire.

In various embodiments, a sensor may have one wire, two wires, or morethan two wires extending from the housing and functioning as antennas.

In one embodiment, the portion of the wire that is external to thehousing has a selected length. The signal containing the measurementinformation has a wavelength related to the length of the wire.Advantageously, a relationship between the length of the wire and thewavelength of the signal is selected to cause resonance in the wire andthereby boost the strength of the signal.

Advantageously, the relationship between the wire length and signalwavelength of a sensor embedded in a concrete mixture may increase thestrength of a signal received from the sensor, for example, by a Wifirouter located at a selected distance from the concrete mixture. As aresult, the WiFi router may receive a higher quality signal and/or bepositioned at a larger distance from the concrete mixture.

Various relationships between the wire length and signal wavelength maybe used. For example, in accordance with an embodiment, the length ofthe wire external to the housing is one-half the wavelength of thesignal transmitted via the wire. In another embodiment, the length ofthe wire is equal to one-fourth the wavelength of the signal. In anotherembodiment, the length of the wire is equal to the wavelength of thesignal. In another embodiment, the length of the wire is twice thewavelength of the signal. In other embodiments, the length of the wireis equal to a selected multiple of the wavelength. Other relationshipsmay be used.

FIG. 37 shows a sensor device in accordance with an embodiment. Sensor3700 includes a housing 3710, a first wire 3740 extending from thehousing, and a second wire 3750 extending from the housing. The wiresmay be insulated, or may not have insulation. Sensor device 3700includes one or more sensors adapted to obtain measurements relating toa concrete mixture. The length of the portion of first wire 3740 that isexternal to housing 3710 is L1. The length of the portion of second wire3750 that is external to housing 3710 is L2.

FIG. 38 shows a communication system in accordance with an embodiment.Communication system 3800 includes sensor device 3700 and a WiFi router3890. A form 3805 contains a concrete mixture 3825. Sensor device 3700is embedded in concrete mixture 3825. Wires 3740 and 3750 are alsoembedded in concrete mixture 3825. Wires 3740 and 3750 transmit signalsrelating to measurements obtained by sensor device 3700. WiFi router3890 is located at a selected distance from sensor device 3700. WiFirouter 3890 receives signals from sensor device 3700 and transmits them,for example, to a second device, or to a network.

FIG. 39 shows a communication system in accordance with anotherembodiment. Communication system 3900 includes sensor device 3700 and aWiFi router 3990. A form 3905 contains a concrete mixture 3925. Sensordevice 3700 is embedded in concrete mixture 3925. Wires 3740 and 3750are also embedded in concrete mixture 3925. Wires 3740 and 3750 arearranged so that they extend from sensor device 3700 up to and above thesurface of concrete mixture 3925. Wires 3740 and 3750 transmit signalsrelating to measurements obtained by sensor device 3700. WiFi router3990 is located at a selected distance from sensor device 3700. WiFirouter 3990 receives signals from sensor device 3700 and transmits them,for example, to a second device, or to a network.

FIG. 40 shows a sensor device in accordance with another embodiment. Thesensor device includes a shell 4020 that may comprise plastic, forexample, or another material. Shell 4020 may include two or moreportions and may be sealed, for example. A printed circuit board (PCB)4035 that holds one or more sensors (e.g., humidity, temperaturesensors, etc.) is disposed inside shell 4020. PCB 4035 also includes anantenna adapted to transmit a signal containing measurement information.A wire is wound around shell 4020 to form a plurality of coils 4062. Thewire is formed of a conductive material. First and second ends 4064 ofthe wire extend from shell 4020. In one embodiment, the length of thewire wound around shell 4020 is related to the wavelength of a signaltransmitted by PCB 4035 (e.g., one-half the wavelength of the signal,one-fourth the wavelength of the signal, etc.).

FIG. 41 shows a concrete mixture containing several sensor devices inaccordance with an embodiment. Form 4110 includes a concrete mixture4120. A first sensor device 4100 with a plurality of coils and anantenna 4190 is embedded at a selected depth in the concrete mixture. Aportion 4150 of antenna 4190 extends above the surface of the concretemixture. A second sensor device 4105 has a second plurality of coils butdoes not have a wire extending above the surface of the concrete. Secondsensor device 4105 is embedded in the concrete proximate to or adjacentto first sensor device 4100. For example, the two sensors may touch eachother. Alternatively, the two sensors may be separated by a smalldistance (e.g., less than one inch). The coils of first sensor device4100 respond to first signals generated by a printed circuit boardinside sensor device 4100; the first signal (or a related signal) istransmitted via antenna 4190 to a remote device. The coils of sensordevice 4100 also respond to second signals generated by a printedcircuit board inside second sensor device 4105, and the antenna 4190transmits the second signals (or a related signal) via antenna 4190. Forexample, antenna 4190 may transmit the signals to a WiFi station.

In accordance with another embodiment, a sensor device includes aprinted circuit board with sensors coated entirely or partially with aprotective material. FIG. 42 shows a cross-section of a sensor device inaccordance with an embodiment. Sensor device 4200 includes a printedcircuit board (PCB) 4210 that includes a plurality of sensors 4215.Sensors 4215 may include, for example, temperature sensors, humiditysensors, salinity sensors, conductivity sensors, motion sensors, pHsensors, etc. All or a portion of the surface of PCB 4210 is covered bya protective coating material 4230, which may be rubber or plastic, forexample. The protective coating material may be waterproof, for example.The coating material protects the sensors on PCB 4210 from water, forexample.

In one example, sensor device 4200 may be formed by applying a liquidrubber material to the surface of PCB 4210. In another embodiment, aliquid plastic material may be applied.

FIG. 43 shows a sensor device in accordance with another embodiment.Sensor device 4300 includes PCB 4210, which is covered by material layer4230 and encased in a case 4320. Case 4320 may be formed of plastic, forexample.

FIG. 44 shows a sensor device in accordance with another embodiment.Sensor device 4400 includes PCB 4210 (with sensors 4215), which iscovered by material layer 4230. Sensor device 4400 also includes a wire4490 wound around PCB 4210 and material layer 4230, forming a pluralityof coils. Wire 4490 is formed of a conductive material. First and secondends of the wire may be used as an antenna, for example.

As mentioned above, in various embodiments, predictions of maturity,strength, and other characteristics may be generated based onmeasurement data received from one or more sensing devices.Relationships between curing temperature of a concrete mixture and thematurity of the concrete mixture, and between curing temperature of aconcrete mixture and the strength of the concrete mixture arewell-known. For example, relationships between curing temperature of aconcrete mixture and the maturity of the concrete mixture, and betweencuring temperature of a concrete mixture and the strength of theconcrete mixture are discussed in several standards established by ASTMInternational such as ASTM 1074. Additional examples of relationshipsbetween curing temperature and strength and between curing temperatureand maturity are found in Burg, Ronald G., “The Influence of Casting andCuring Temperature on The Properties of Fresh and Hardened Concrete,”Portland Cement Association: Research and Development Bulletin, ISBN0-89312-143-6, Skokie, Ill., 1996.

The foregoing Detailed Description is to be understood as being in everyrespect illustrative and exemplary, but not restrictive, and the scopeof the invention disclosed herein is not to be determined from theDetailed Description, but rather from the claims as interpretedaccording to the full breadth permitted by the patent laws. It is to beunderstood that the embodiments shown and described herein are onlyillustrative of the principles of the present invention and that variousmodifications may be implemented by those skilled in the art withoutdeparting from the scope and spirit of the invention. Those skilled inthe art could implement various other feature combinations withoutdeparting from the scope and spirit of the invention.

The invention claimed is:
 1. A system comprising: a sensor devicecomprising a housing, a sensor adapted to generate measurement datarelating to a characteristic of a concrete mixture, and a transmittingdevice adapted to transmit a first signal based on the measurement data,the sensor and the transmitting device being disposed in the housing; aconductive wire forming a coil having a plurality of loops around thehousing; wherein the coil is adapted to generate an electric current inresponse to the first signal; wherein the coil is adapted to transmit asecond signal based on the electric current.
 2. The system of claim 1,wherein the coil includes at least five loops.
 3. The system of claim 1,wherein the conductive wire comprises a metal.
 4. The system of claim 3,wherein the conductive wire comprises an insulated metal wire.
 5. Thesystem of claim 1, wherein the characteristic is one of: temperature,sonic signal strength, acceleration, motion, pH, inductance, impedance,resistivity, pressure, conductivity, salinity, humidity, and elevation.6. The system of claim 1, wherein the sensor device comprises a printedcircuit board having a plurality of sensors.
 7. The system of claim 6,wherein the plurality of sensors include one of: a temperature sensor, asonic sensor, an acceleration sensor, a motion sensor, a pH sensor, aninductance sensor, an impedance sensor, a resistivity sensor, a pressuresensor, a conductivity sensor, a salinity sensor, a humidity sensor, andan elevation sensor.
 8. The system of claim 1, wherein the sensor deviceis covered by a layer of a protective material.
 9. A sensor devicecomprising: a housing; a sensor adapted to obtain a measurement; a wireextending from the housing, the wire having a length, the wire adaptedto function as an antenna; and a transmitter adapted to transmit asignal via the wire, the signal having a wavelength selected based onthe length of the wire.
 10. The sensor device of claim 9, wherein thesignal includes information relating to the measurement.
 11. The sensordevice of claim 9, wherein the wavelength of the signal is one of: twicethe length of the wire, the length of the wire, one-half the length ofthe wire, and one-fourth the length of the wire.
 12. A communicationsystem comprising: a concrete mixture; the sensor device of claim 9,wherein the sensor device is embedded in the concrete mixture; and awireless router adapted to receive signals from the sensor device. 13.The communication system of claim 12, wherein the wire is entirely belowa surface of the concrete mixture.
 14. The communication system of claim12, wherein the wire extends above a surface of the concrete mixture.15. The communication system of claim 12, wherein the sensor includesone of a temperature sensor, an accelerometer, a pH sensor, aninductance sensor, an impedance or resistivity sensor, a sonic sensor, apressure sensor, a conductivity sensor, a salinity sensor, a humiditysensor, and an elevation sensor.
 16. A device comprising: a printedcircuit board comprising a first edge, a second edge, a surface locatedbetween the first and second edges, one or more sensors adapted toobtain measurement data, and a first antenna adapted to transmit a firstsignal based on the measurement data, the first antenna disposed betweenthe first and second edges; a layer of a waterproof protective materialcovering at least a portion of the printed circuit board; and aconductive wire having a first portion that is wound around the firstedge, the second edge, and the first antenna of the printed circuitboard to form a plurality of coils, and a second portion that functionsas a second antenna; wherein: the plurality of coils of the conductivewire responds to the first signal due to inductive coupling, therebygenerating a second signal; and the second antenna transmits the secondsignal.
 17. The device of claim 16, wherein the device is embedded in aconcrete mixture.
 18. A system comprising: a concrete mixture; thesensor device of claim 16 embedded in the concrete mixture; and awireless router disposed at a selected distance from the concretemixture.
 19. The sensor device of claim 16, wherein the waterproofprotective layer comprises one of rubber and plastic.
 20. The sensordevice of claim 16, wherein the printed circuit board comprises one of atemperature sensor, a humidity sensor, an accelerometer, a pH sensor, aninductance sensor, an impedance or resistivity sensor, a sonic sensor, apressure sensor, a conductivity sensor, a salinity sensor, and anelevation sensor.